1 /* $NetBSD: if_agrether_hash.c,v 1.3 2007/05/05 18:23:23 yamt Exp $ */ 2 3 /*- 4 * Copyright (c)2005 YAMAMOTO Takashi, 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: if_agrether_hash.c,v 1.3 2007/05/05 18:23:23 yamt Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/mbuf.h> 34 #include <sys/hash.h> 35 36 #include <net/if.h> 37 #include <net/if_dl.h> 38 #include <net/if_ether.h> 39 #include <net/if_vlanvar.h> 40 41 #include <net/agr/if_agrethervar.h> 42 43 #include <netinet/in.h> 44 #include <netinet/in_systm.h> 45 #include <netinet/ip.h> 46 #include <netinet/ip6.h> 47 48 #define HASH(p, l, h) hash32_buf((p), (l), (h)) 49 50 static const void *agr_m_extract(struct mbuf *, int, int, void *); 51 52 static const void * 53 agr_m_extract(struct mbuf *m, int off, int len, void *buf) 54 { 55 const void *result; 56 57 KASSERT((m->m_flags & M_PKTHDR) != 0); 58 59 if (m->m_pkthdr.len < off + len) { 60 result = NULL; 61 } else if (m->m_len >= off + len) { 62 result = mtod(m, char *) + off; 63 } else { 64 m_copydata(m, off, len, buf); 65 result = buf; 66 } 67 68 return result; 69 } 70 71 uint32_t 72 agrether_hashmbuf(struct agr_softc *sc, struct mbuf *m) 73 { 74 struct ether_header eh_store; 75 const struct ether_header *eh; 76 uint32_t hash = HASH32_BUF_INIT; 77 int off = 0; 78 uint16_t tci; 79 uint16_t etype; 80 struct m_tag *mtag; 81 82 eh = agr_m_extract(m, off, sizeof(*eh), &eh_store); 83 if (eh == NULL) { 84 return hash; 85 } 86 87 hash = HASH(&eh->ether_dhost, sizeof(eh->ether_dhost), hash); 88 hash = HASH(&eh->ether_shost, sizeof(eh->ether_shost), hash); 89 etype = eh->ether_type; 90 91 if (etype == htobe16(ETHERTYPE_VLAN)) { 92 struct ether_vlan_header vlanhdr_store; 93 const struct ether_vlan_header *vlanhdr; 94 95 vlanhdr = agr_m_extract(m, off, sizeof(*vlanhdr), 96 &vlanhdr_store); 97 if (vlanhdr == NULL) { 98 return hash; 99 } 100 101 tci = vlanhdr->evl_tag; 102 etype = vlanhdr->evl_proto; 103 off += sizeof(*vlanhdr) - sizeof(*eh); 104 } else if ((mtag = m_tag_find(m, PACKET_TAG_VLAN, NULL)) != NULL) { 105 tci = htole16((*(u_int *)(mtag + 1)) & 0xffff); 106 } else { 107 tci = 0; 108 } 109 hash = HASH(&tci, sizeof(tci), hash); 110 111 off += sizeof(*eh); 112 if (etype == htobe16(ETHERTYPE_IP)) { 113 struct ip ip_store; 114 const struct ip *ip; 115 116 ip = agr_m_extract(m, off, sizeof(*ip), &ip_store); 117 if (ip == NULL) { 118 return hash; 119 } 120 121 hash = HASH(&ip->ip_src, sizeof(ip->ip_src), hash); 122 hash = HASH(&ip->ip_dst, sizeof(ip->ip_dst), hash); 123 hash = HASH(&ip->ip_p, sizeof(ip->ip_p), hash); 124 125 /* use port numbers for tcp and udp? */ 126 127 } else if (etype == htobe16(ETHERTYPE_IPV6)) { 128 struct ip6_hdr ip6_store; 129 const struct ip6_hdr *ip6; 130 uint32_t flowlabel; 131 132 ip6 = agr_m_extract(m, off, sizeof(*ip6), &ip6_store); 133 if (ip6 == NULL) { 134 return hash; 135 } 136 137 hash = HASH(&ip6->ip6_src, sizeof(ip6->ip6_src), hash); 138 hash = HASH(&ip6->ip6_dst, sizeof(ip6->ip6_dst), hash); 139 /* hash = HASH(&ip6->ip6_nxt, sizeof(ip6->ip6_nxt), hash); */ 140 141 flowlabel = ip6->ip6_flow & IPV6_FLOWLABEL_MASK; 142 hash = HASH(&flowlabel, sizeof(flowlabel), hash); 143 144 /* use port numbers for tcp and udp? */ 145 } 146 147 return hash; 148 } 149